From a92a7edf38d8df650bb7fb63195c04ce38b88e2a Mon Sep 17 00:00:00 2001
From: Kuniyuki Iwashima <kuniyu@amazon.com>
Date: Mon, 18 Jul 2022 10:26:40 -0700
Subject: [PATCH 24/28] ipv4: Fix data-races around
sysctl_fib_multipath_hash_policy.
Git-commit: 7998c12a08c97cc26660532c9f90a34bd7d8da5a
Patch-mainline: v5.19-rc8
References: git-fixes
While reading sysctl_fib_multipath_hash_policy, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its readers.
Fixes: bf4e0a3db97e ("net: ipv4: add support for ECMP hash policy choice")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 2 +-
net/ipv4/route.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index e2ada534057f..60a231916518 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -9575,7 +9575,7 @@ static void mlxsw_sp_mp4_hash_init(struct mlxsw_sp *mlxsw_sp,
unsigned long *fields = config->fields;
u32 hash_fields;
- switch (net->ipv4.sysctl_fib_multipath_hash_policy) {
+ switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) {
case 0:
mlxsw_sp_mp4_hash_outer_addr(config);
break;
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 94e33d3eaf62..c056c58db629 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2044,7 +2044,7 @@ int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4,
struct flow_keys hash_keys;
u32 mhash = 0;
- switch (net->ipv4.sysctl_fib_multipath_hash_policy) {
+ switch (READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_policy)) {
case 0:
memset(&hash_keys, 0, sizeof(hash_keys));
hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
--
2.16.4